const logger = require('./logger.js');
const commands = require('./commands.js');
const constants = require('./constants.js');

async function getServiceState(name) {
    if (name === undefined) {
        return;
    }
    logger.debug('checking service \'' + name + '\'...');
    const state = await commands.execute('systemctl', ['is-active', name], true);
    logger.debug('state of service \'' + name + '\' is \'' + state + '\'');
    return { service: name, state: state };
}

async function setServiceState(name, args) {
    if (name === undefined || args === undefined) {
        return;
    }
    let state = args.get('state');
    if (state === undefined) {
        return;
    }
    if (state !== constants.SYSTEMD_STATE_ACTIVE && state !== constants.SYSTEMD_STATE_INACTIVE && state !== constants.SYSTEMD_STATE_TOGGLE) {
        const msg = 'can not set state of service \'' + name + '\' to unknown state \'' + state + '\'';
        logger.debug(msg);
        return { err: msg };
    }
    let service = await getServiceState(name);
    if (state !== constants.SYSTEMD_STATE_TOGGLE && service.state === state) {
        const msg = 'service \'' + name + '\' is already in state \'' + service.state + '\'';
        logger.debug(msg);
        return { msg: msg };
    }
    let command;
    if (service.state === constants.SYSTEMD_STATE_ACTIVE) {
        command = 'stop';
        state = constants.SYSTEMD_STATE_INACTIVE;
    } else if (service.state === constants.SYSTEMD_STATE_INACTIVE) {
        command = 'start';
        state = constants.SYSTEMD_STATE_ACTIVE;
    }
    logger.debug('setting state of service \'' + name + '\' to \'' + state + '\'...');
    return { service: name, state: state, result: await commands.execute('systemctl', [command, name], true)};
}

module.exports = {
    getServiceState,
    setServiceState
}